Changes of yield of silage maize depending on plants density, maturity during harvest and height of harvest

Summary.

The field experiment with maize tillage was carried out in the years 1996-1997 in Napachanie, near Poznań. The influence of plants density (7 and 9 plants per 1 m2), harvest term and maize cutting height of ‘Greta’ FAO 230-240 variety on yield losses was investigated. The harvest was in three terms: milk-waxen, waxen and at the beginning of full maturity and the plants were cut at 15, 40 and 65 cm over the ground. As the research showed, along with an increasing vegetation, the fresh mass of stalks left on the field was systematically decreasing. In milk-waxen maturity the organic matter amounted average 142.4 dt/ha, in waxen maturity – 124.2 dt/ha and at the beginning of full maturity it was 106.9 dt/ha. Raising the cut height during the harvest caused the leaving of bottom sections of stalks. Harvest at 40 cm of cut height the yield losses of dry matter in both research years amounted 72.5 dt/ha, whereas the yields of dry matter were lower of approximately 11.5 dt/ha in comparison with harvest at 15 cm. During harvest on 65 cm there was 52 dt/ha of fresh matter in the stubble, which amounted 10 dt/ha in dry matter. The growth of cut height during the harvest in a higher rate influenced decrease of yields in fresh matter, and to a lower level decrease of yields in dry matter.